M2M Ring Mega Nitrile Small Black. Nitrile is the same material used to make gloves for emergency room doctors and nurses. Why Nitrile? Because Nitrile is 100% skin safe and hypoallergenic. Nitrile is also compatible and safe to use with all types of lubricants. Nitrile is stronger and holds its shape better than latex or rubber and it stretches slightly to achieve maximum constriction without sacrificing comfort. Nitrile is available in a wide variety of colors, sizes and thicknesses. If you are looking for an inexpensive and versatile cock ring, nitrile is the perfect choice. Why use a Cock Ring? The role of a cock ring is to provide constriction, this constriction slows the flow of blood from the erect penis creating an erection that not only lasts longer but is also thicker and harder. Prolong rings helps prevent early ejaculation.